324 H. C. COOKE 



be said of the remainder of this section, since the rocks above the 

 conglomerate are broken and replaced by a large mass of intrusive 

 porphyry. To the south of the porphyry on Bear Lake, however, 

 a new formation appears, a thin-bedded argillite of about the same 

 composition as the greywacke. 



The basal conglomerate was next observed on the west end of 

 Barber Lake, about a mile to the east of Bear Lake. In this dis- 

 tance it has thinned remarkably to only 60 feet. It is overlain 

 by about 100 feet of rather impure sandstone, to the south of which 

 lie the greywacke and argillites of the series. The thickness of the 

 latter was not directly determined and cannot be estimated, since 

 the southern edge of the synchne is covered by Larder Lake. The 

 conglomerate band outcrops along the south shore of Barber 

 Lake, continuing to thin, until about a quarter of a mile east of the 

 east end it was observed to consist of about a foot of rather coarse 

 grit. It was not found again on the south side of the anticlinal 

 nose here (Fig. 2), so that the base of the series for at least half of 

 a mile appears to be a rather impure sandstone. As this is very 

 badly sheared, however, for a width of perhaps 25 feet from the 

 contact, and converted into a featureless sericite schist, it is possible 

 Ihat pebbles may have existed in it but were obliterated. 



On the north side of the anticlinal nose, the conglomerate 

 reappears again, gradually thickening to about 30 feet. It con- 

 sists, like that around Binney Lake, of thin pebbly beds inter- 

 stratified with beds of greywacke. It maintains this character 

 east of Beaver Lake, where the syncline (Fig. 2) pinches out. On the 

 north side of this syncline, for a distance of about 2 miles east of 

 Beaver Lake, the conglomerate is hidden by drift, and where it 

 reappears it is a rather thin band, perhaps 30 or 40 feet in thick- 

 ness, over which lies about 700 feet of rather impure quartzite. 

 This is overlain in turn by a second band of conglomerate about 

 300 feet thick. To the south of this band of conglomerate the rocks 

 are grits and impure quartzites, very poorly exposed. To the 

 east, the lower conglomerate disappears entirely within a mile, 

 replaced by beds of impure quartzite intruded by masses of por- 

 phyry. The total width of this mixture is i ,400 feet, of which about 

 three-fourths is porphyry. To the south of this Hes nearly 1,000 



